I think this line:
We recommend however that users upgrade via My OSMC . Upgrading via My OSMC will still ensure that all Debian packages are upgraded.
Should be higher up the page.
I went the
sudo apt-get update sudo apt-get dist-upgrade
route and now my ATV wont boot.
I had only 20 minutes before installed OSMC for the first time via the USB stick
Now when it boots, a blue screen with sad face flashes up and nothing else happens